Heat 1 teaspoon oil in a large nonstick skillet over medium-high heat. Stir in corn and crushed red pepper. Sauté 2 to 3 minutes or until corn is lightly browned. Add bell pepper; sauté 2 minutes. Stir in chicken and green onions; sauté 1 minute. Remove mixture from heat; stir in oregano, cilantro, and salt. Wipe pan dry with a paper towel.
Sprinkle each of 4 tortillas with 1 1/2 tablespoons cheese, and top evenly with chicken mixture. Sprinkle remaining cheese evenly over chicken mixture, and top with remaining 4 tortillas.
Place pan over medium heat and add 1/4 teaspoon oil. Carefully add 1 quesadilla, and cook 2 to 3 minutes on each side or until lightly browned. Repeat procedure with remaining oil and quesadillas. Cut each quesadilla into 4 wedges. Serve immediately.